About Coronaviruses
Coronaviruses are small infectious agents, commonly known as viruses, that replicate inside the living cells of their hosts. Some examples of Coronaviruses include SARS virus, MERS virus and novel coronavirus (2019-nCoV – Wuhan coronavirus). Viruses can infect all types of life forms including humans, animals, plants and microorganisms etc.
There are two main groups of viruses, enveloped and non-enveloped viruses, based on their structure. Coronaviruses are a type of enveloped viruses. This means that Coronaviruses have a lipid envelope in their structure. The lipid envelope is relatively sensitive to desiccation, heat and detergents. Hence Coronaviruses are more easily inactivated by biocidal active substances than their non-enveloped cousins.
List of Common Active Substances
Here is a list of biocidal active substances that are effective against lipophilic viruses below. The list also includes their odour characteristics and recommended pH range for formulation purposes.
Active
|
Lipophilic viruses
| Odour |
Recommended pH range
| |
Quaternary ammonium compound
|
Effective
| Low |
4-10
| |
Dodecyl dipropylene triamine
|
Effective
| Low |
4-9 | |
Aldehyde
|
Effective
|
Strong
|
3-10
| |
Hypochlorite
|
Effective
|
Strong
|
5-8 | |
Phenolics
|
Effective
|
Strong
|
<9
| |
Peracetic acid
|
Effective
| Strong |
<8 | |
Alcohols
|
Effective
|
Moderate
|
n.a.
|
A basic laundry detergent formulation comprises at least a cleaning surfactant, typically anionic, to remove the soil from fabric. Some of the most common anionic surfactant in laundry detergent formulation include Sodium Lauryl Ether Sulfate (SLES), linear alkyl benzene sulfonate and alpha olefin sulfonate.
Most laundry detergent formulation in Asia contain a chelating agent to remove the calcium and magnesium ions. These ions are present in hard water, common in Asia, and they interfere with the cleaning mechanism of surfactant.
Anti-microbial Laundry Detergent Formulation
One method of incorporating anti-microbial properties in laundry detergent is simply to add the biocidal active substances into the formulation. A basic laundry detergent formulation can be as follows:
SLES 10%, dodecyl dipropylene triamine (Triameen Y12D) 1%, Tetrasodium Glutamate Diacetate (Evermild GLDA).
SLES serves as the cleaning surfactant while Tetrasodium Glutamate Diacetate is the chelating agent.
Dodecyl dipropylene triamine is selected over the other biocidal active substances for the laundry detergent formulation for the following reasons.
- Dodecyl dipropylene triamine is a surfactant and can be easily incorporated into a surfactant-based laundry detergent formulation.
- Dodecyl dipropylene triamine is non-ionic and compatible with the anionic SLES in the formulation.
Quaternary ammonium compound, which is another surfactant active, is not chosen because it is cationic and not compatible with SLES. There are also studies that show dodecyl dipropylene triamine performing better than quaternary ammonium compound.